Actors Melissa Gilbert and Timothy Busfield engaged

Melissa Gilbert is engaged to marry Timothy Busfield, formerly of "thirtysomething" and "The West Wing," People magazine reports.

"They got engaged over the holidays," a source told Us Weekly, which first broke the news. "They've known each other for quite some time, as their paths have crossed off-and-on over the past 20 years."

In addition to acting, Busfield is a TV director. "Little House on the Prairie" star Gilbert performed last year on "Dancing With the Stars," where she partnered with Maksim Chmerkovskiy and finished fifth.

It will be a third marriage for both actors. Gilbert, 48, is a mother of two, and was previously married to Bo Brinkman and Bruce Boxleitner. The split with Boxleitner was finalized in 2011. Busfield, 55, is a father of three and was married to Radha Delmarter and then Jennifer Merwin. His second marriage, which ended in 2007, lasted nearly 20 years, People said.